The present invention generally relates to the production of chocolate by an improved process and system. More particularly, the invention relates to chocolate production that includes imparting a substantially constant power level to the chocolate refinings being conched. Included is an arrangement for varying the drive speed of the conching equipment in response to the changing consistency of the intermediate chocolate product being conched. The invention enhances chocolate production efficiency by making additional energy available in order to achieve one or more advantages, especially reduction in processing times and optimization of the addition of costly ingredients such as cocoa butter.
Chocolate is a mixture of finely milled solids, chocolate liquor, sugar, milk crumb or powder, all suspended or well dispersed in cocoa butter and/or substitute fat, which at normal processing temperatures is the liquid carrying medium. Raw materials such as chocolate liquor, sugar, water and milk are processed into chocolate through a series of processed steps including, for example, crumb making, paste mixing, refining, conching and standardizing. Usually, an emulsifier or an emulsifying system is added during conching.
During conching, chemical and physical processes take place. These include the development of the full desirable chocolate flavor and the conversion of the powdery, crumbly refined product into the chocolate. Conching imparts shearing stresses and kneading action which serve both to liquify the masse and to positively influence and accelerate the flavor development processes. Important physical tasks of conching are to disperse, to dehumidify or remove moisture, to remove unwanted volatile flavors, to break up solid particle agglomerates, to round particle edges and to homogenize. Viscosity is lowered, and flowability and texture are improved.
It is generally accepted that longer conching times produce better chocolate. Enough time is needed to develop proper texture, good mechanical properties, good flavor and the like. A good conching procedure carefully works the chocolate refinings in order to remove undesirable volatiles while releasing other flavor notes that contribute to taste and odor qualities desired of the particular chocolate being manufactured. Conching also effects a natural moisture reduction, a typical chocolate product having moisture levels of below one percent by weight. While longer conching times are generally preferred, commercial chocolate-making operations do place a premium on efficiency. Ideally, this efficiency should not be at the expense of desirable chocolate attributes. For example, chocolate attributes are affected by conching power and heat development. While it is generally beneficial to impart adequately high power levels during conching, the power imparted to the materials being conched should be kept congruent with the consistency of the product itself in order to most appropriately achieve the benefits of conching. While a temperature rise can be a characteristic of many conching procedures, uncontrolled heat development caused by conching friction can result in off-flavors.
Conching procedures and equipment have evolved over the years. Early conches were of the longitudinal type having long marble tubs with raised sides forming a shell. In this shell, an undulating granite roller worked and mixed the chocolate for from 24 to 36 hours. Later, classical vertical mixers such as those developed by Petzholdt were able to reduce conching time to between about 5 to 8 hours by using plow and shear blades to tumble dry refinings in the beginning of dry conching and then, when the mass is plasticized, put energy into the material being conched. Another current rotary conch incorporates a horizontal mixer design which has three shafts with kneading and shearing blades attached. The center blade rotates in one direction and the two outboard shafts rotate the opposite direction, which directions are reversed when desired. These types of horizontal rotary conches provide a so-called "double-overthrow" action to thoroughly mix and bring new material into its high shear zones in order to shorten the dry conching cycle time. Conches of this type, which are available from Richard Frisse GmbH keep the scraping surfaces as large as possible to provide good shearing stress. Scrapers and kneader stirrer arms on the horizontal shafts overlap one another, providing powerful shearing in the masse and at the walls.
During the course of the operation of traditional conching devices such as these, the conching agitators rotate at a constant forward speed. During the course of such a traditional operation, the power imparted to the intermediate product being conched will vary over time, particularly as it begins to plasticize or when ingredients are added to the batch which have a primarily liquid consistency. This traditional approach can include two drive motors, one for forward operation at one constant speed (dry conch), and the other for reverse operation at another (usually faster) constant speed (wet conch).
A possible alternative approach to improve conching would incorporate a drive arrangement that includes a primary drive motor and a secondary drive motor. The primary one would impart a relatively slow speed to the conching members, while the secondary drive motor would impart a faster speed. Through suitable mechanical arrangements, this dual motor approach would attempt to improve conching by having it take place at two different speeds. In essence, by this approach, a higher power input would be imparted to the conching device when deemed appropriate. That is, for any interval of time, the product being conched would offer a total resistance within the full load torque capability of the motor. One consequence would be to have higher input power intermittently "forced" into the product. However, imparting excessive energy too rapidly tends to form "grit" or hard, small particles that will remain within the finished chocolate, such typically being undesirable in most applications.
Another example of the delicacy of the balance which needs to be maintained in order to provide consistent, superior chocolate products on a commercial scale is the difficulty in achieving the proper viscosity of the finished chocolate in a time-efficient manner. Chocolate viscosity must be low enough in order to facilitate subsequent activities such as enrobing or molding. In most applications, viscosity reduction requires the incorporation of an emulsifier such as lecithin. Traditionally the lecithin addition is carried out at the beginning and/or near the end of the conching operation.
In summary, the present invention is a process and apparatus or system for producing chocolate, with conching being a major step in the system. Chocolate refinings are subjected to conching conditions that are substantially determined by the varying consistency of the ingredients themselves while they are being conched. The present invention has recognized advantages will result from a feedback arrangement wherein the consistency of the material being conched is itself "fed back" to control the conching. By the use of a variable drive arrangement, the conching speed is automatically varied, depending largely upon the viscosity of the ingredients being conched, to such an extent that the power imparted to the ingredients is maintained substantially constant virtually throughout the conching procedure. In addition to varying the conching speed in order to maintain the conching power, the feedback provided by the interaction between the ingredients being conched and the conching equipment can also be used to control ingredients, such as addition of fat or emulsifier, and/or processing conditions used in the conching procedure, such as direction of blade rotation.
It is accordingly a general object of the present invention to provide an improved process and apparatus or system for making chocolate.
Another object of the present invention is to provide an improved process and system which accomplishes chocolate-making by utilizing feedback of data from a conching operation in order to control the conching conditions and/or conching ingredients.
Another object of the present invention is to provide an improved process and apparatus wherein conching is carried out in a manner to maintain substantially constant power input to the equipment effecting the conching procedure and to the chocolate refinings being conched.
Another object of this invention is to provide an improved process and apparatus or system to make chocolate while reducing processing times and/or while optimizing the addition of costly ingredients such as cocoa butter.
Another object of the present invention is to provide an improved procedure and system for producing chocolate which maximizes the efficiency with which conching equipment is used while maintaining the proper consistency of the final chocolate product.
Another object of this invention to provide an improved process and apparatus which protects and respects the delicate, natural system of chocolate.
Another object of the present invention is to provide an improved chocolate-making process and system which substantially avoids grit formation while optimizing processing times.
Another object of the present invention is to provide an improved process and system of producing chocolate which makes chocolate that is especially consistent.
Another object of this invention is an improved process which is universal in its application to conching having the characteristic of an intrinsic rapid decline of the power imparted to the chocolate during the conching cycle.
These and other objects, features and advantages of the invention will be clearly understood through a consideration of the following detailed description.